I found the cause of the problem. When and if you want this command to work, the VNC server HAS TO BE ALREADY RUNNING in "service" or "user" mode.
The 2nd important thing to keep in mind, that you have to launch the matching command: 1. If you have the VNC Server service running, this is the command that will work: "C:\Program Files\RealVNC\VNC4\winvnc4.exe" -service -connect <ip address> 2. If you have the VNC server running in "User mode" this is the command that will work: "C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect <ip address> Basically, when you launch either of the commands, you are not starting another application, but a "sub-application of some sort" of winvnc4.exe that is already running. Until now I (and probably many other folks with the same problem) was assuming that running the command line version by itself should work. In my case the problem was caused by two things: I don't run VNC server on my computers because I don't have the need for it. I told my friend not to run it either, that's why the command line version never worked and even after he turned on the VNC server service on his computer, the command line still didn't work because he was trying to use the "user mode" version of the command line that was looking for the "user mode" VNC server. This stuff seems like a trivial one once you understand how it works, but in fact it is not. In my opinion the trivial one would be if you could launch it from the command line without the prerequisite of having the matching VNC server running - this should have been part of the RealVNC manual for a long time and the FAQs too. Geza -----Original Message----- From: Philip Herlihy [mailto:phi...@herlihy.eu.com] Sent: Monday, March 01, 2010 4:03 AM To: 'Geza Levai' Subject: RE: Command line version of connecting to listening viewer doesn't work I'm afraid I can't shed any light on your connection problem - the equivalent commands work for me. Do you have any security software on the server box that might be interfering? Yes, you're right in your understanding of what my script does. However, the situation is certainly different on Vista and 7 and I haven't had a chance to investigate. Philip Herlihy -----Original Message----- From: Geza Levai [mailto:g...@pumi.org] Sent: 28 February 2010 23:18 To: 'Philip Herlihy' Subject: RE: Command line version of connecting to listening viewer doesn't work Philip, I am getting an error message "Unable to locate existing VNC Server". I tried it with :5500, ::5500 and without any port designation. I am doing these tests on my home network with two computers, both of them have XP Pro sp3. BUT THE MOST IMPORTANT FACT IS THAT THERE IS NO PROBLEM CONNECTING TO THE LISTENING VIEWER COMPUTER BY RIGHT CLICKING ON THE VNC SERVER ICON IN THE SYSTEM TRAY AND ADDING THE IP ADDRESS TO THE DIALOG WINDOW "Connect to listening VNC Viewer". I also tried to connect to the listening computer using telnet, the connection was successful. So, the bottom line is, that using the GUI interface there is no problem at all, using the command line interface it gives the error message "Unable to locate existing VNC Server". "C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect computer2 I think either I am not using the correct syntax or RealVNC has a programming error or bug in it and it cannot interpret its own command line commands. What is interesting is that I did a Google search on this problem, and I found numerous postings about the same problem with RealVNC, but not one had a solution to this problem. About your cmd utility: did I understand it correctly that you supposed to run it on the server end, so that if the connection gets lost, it will be restored from the server end without human interaction? Will that work on Windows Vista and Windows 7 if you get bumped out by the UAC? Geza -----Original Message----- From: Philip Herlihy [mailto:phi...@herlihy.eu.com] Sent: Friday, February 26, 2010 5:45 AM To: 'Geza Levai'; vnc-list@realvnc.com Subject: RE: Command line version of connecting to listening viewer doesn't work To debug a thing like this, run it in a command window, so you can see any error messages. I believe the problem may be with the trailing :5500 - I've never needed to specify this at the server end, only to set up port-forwarding on the firewall at the receiving (client) end. Take that off and it should work. You may be interested in a command script I've developed to keep checking for an established connection and re-connect if it has dropped (something I developed when trying to manage a system in Ghana from my location in London). You can find it here: http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd http://cid-2e572770a3a5cd55.skydrive.live.com/self.aspx/Public/VNCloop.cmd Philip Herlihy -----Original Message----- From: vnc-list-boun...@realvnc.com [mailto:vnc-list-boun...@realvnc.com] On Behalf Of Geza Levai Sent: 25 February 2010 23:01 To: vnc-list@realvnc.com Subject: Command line version of connecting to listening viewer doesn't work Hi, I am trying to create an icon for connecting to a listening viewer with the information that I gathered about this subject, but it doesn't work. All I can see, that a black DOS command line window pops up for a millisecond in the left upper corner of the screen, but nothing else happens. The same computer has no problem connecting to the listening viewer by having the user typing (copy/pasting) the IP address of the viewer in the window. (The port 5500 on the firewall of the listening viewer is forwarded to the listening computer (otherwise the manual method wouldn't work either, right?) This is the command line that I think should work, but it doesn't: (IP address here is a bogus one, of course) "C:\Program Files\RealVNC\VNC4\winvnc4.exe" -connect 99.999.999.99:5500 Any idea why this command line doesn't work but manually the PC can connect to the listening viewer without any problem? Geza _______________________________________________ VNC-List mailing list VNC-List@realvnc.com To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list _______________________________________________ VNC-List mailing list VNC-List@realvnc.com To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list